Different demographics have different interests, experiences, and knowledge. It's trivially obvious that getting a broader subset of society to contribute will also broaden the content.
With less than 10% of editors being women, for example, content is guaranteed to be somewhat skewed, even assuming absolutely no ill will by anybody.
Among the famous examples are a scientist's entry being deleted as "not notable" just weeks before she won the Nobel Prize. Or, if you prefer quantitative data, that articles about women tend to emphasise their relationships and children (https://arxiv.org/pdf/1501.06307v2.pdf).
Wikipedia wants to be an encyclopedia though, not a bag of personal anecdotes and life experiences.
They want to provide well-sourced information, present the major thoughts where no consensus is visible and do it in a way that every reader can go to the sources and check it. If you want more representation of $group on Wikipedia, you'll do much better by publishing more work of $group's members so that it can be cited and quoted on Wikipedia. Just having them on Wikipedia doesn't/shouldn't work, it's not a news paper where somebody may set the topics/angles to be covered.
And, of course, remember that the article isn't about "knitting", it's about "knitting patterns", so you'd need sources that concern themselves with knitting patterns _as a subject_ and not with individual knitting patterns.
There are very detailed articles about knitting, there's an article about common knitting abbreviations (which I don't believe fits into an encyclopedia, but whatever), there's plenty of other stuff about knitting.
What did you want to see on an article about knitting patterns? And, as a follow-up, why haven't you added that to the article about knitting patterns?